The problem of atmospheric pollution in our cities is caused to a great extent by the polluting discharges from the internal combustion engines of cars which burn fossil fuels. It has, therefore, been recognised that it is necessary to replace such vehicles with non-polluting cars. At present there are non-polluting vehicles driven by batteries which feed electric engines and which are recharged from the electricity grid, ie plug-in. There are also two and four-seater cars which circulate in our cities, similar to ordinary cars, which have photovoltaic panels which are fitted horizontally on the roofs which are themselves substantially horizontal. Some of the cars of this type are equipped with a passive wind fan which the user can fix onto the roof when the car is stationary to capture wind energy in order to recharge the batteries which feed an electric motor which provides traction. Such vehicles are structurally similar to normal cars but are usually built from carbon or resin to reduce their weight.
The problems with such vehicles are the following: the cars which need to be recharged through connection to the grid, ie plug-in, can almost exclusively only be recharged at the point of departure (the distributors of electric energy along our roads is extremely rare) and this limits the diffusion and the practicality of their use and does not resolve the problem of the pollution produced from the polluting electricity centres which provide the grid with the necessary energy. On the other hand the cars which are presently equipped with photovoltaic panels fitted onto the roof which is itself substantially horizontal, have little autonomy due to the length of time necessary for recharging because the extension of the panels, which are in proportion to their power, is limited to the extent that it is equal to that of the design of the vehicle. The same panels, being fitted horizontally, are in an orthogonal position in relation to the sun only under certain conditions and this reduces their efficiency. The wind fan which the user can fit onto the roof of his vehicle is in itself hardly efficient because it is activated by the wind which impacts on the blades at low atmospheric speed.